Determination of attenuation coefficients of single mode optical fiber standards to be used in OTDR calibrations

The subject of this paper is the determination of attenuation coefficients of single mode optical fiber standards used in both loss and distance scales calibrations of OTDR instruments by applying “cut-back” method, and “loop transit time” measurements. In cut-back measurements a modified radiometer with InGaAs having 5 mm diameter active area, cooled to 77 K, was constructed and used. To derive attenuation coefficients after the completion of cut-back measurements, the loop transit time measurements were performed for standard fibers. Total expanded uncertainty was calculated as 3.30×10-3 for determination of attenuation coefficients.